Acoustic transducer arrays are known for use in acoustic or sound imaging applications, wherein the sound-field is sampled at a certain distance from the source of sound using acoustic transducers, and the resulting sound pressure, particle velocity, or sound intensity is measured and visualized. Also, wave-form calculation can be performed before visualization to determine the sound-field on positions other than the original measured positions. Examples of these wave-form reconstruction methods are beam-forming, acoustic holography, and near-field acoustic holography (NAH).
U.S. Pat. No. 7,092,539 discloses a printed circuit board array responsive to aeroacoustic waves. The array comprises a printed circuit board having a first surface and an opposing second surface, and a plurality of sockets distributed over the first surface of the printed circuit board. A plurality of microphone packages are received in the corresponding sockets and contain at least one microphone responsive to an aeroacoustic wave. Each of the microphones includes a semiconductor substrate, a cavity formed in said substrate, a diaphragm covering the cavity, and a vent channel in fluid communication with the cavity and an atmosphere surrounding said array. A signal processor is disposed on the circuit board. An input of the signal processor is coupled to an output of the plurality of microphone packages. The processor beamforms signals received from the plurality of microphone packages and outputs a combined signal therefrom.